Three Part Question
In [patients with presumed GHB intoxication and respiratory depression] is [endotracheal intubation more effective than non-invasive airway management] at [reducing the complications of an unprotected airway]?
A comatose 20 year old male is brought to casualty with a GCS of 3/15 and in respiratory arrest. Acute overdose with gamma-hyroxybutyric acid is suspected. Ventilation is initially assisted with a bag and mask. Your anaesthetic colleagues are very reluctant to intubate the patient as they state that the patient will wake up soon and there are no beds on ITU.
Medline 1966-09/2004 using the OVID interface.
Medline 1966-09/04 using the OVID interface.
[exp Hydroxybutyrates OR gamma hydroxybutyric acid.mp. OR GHB.mp] AND [exp Poisoning OR intoxication.mp OR exp Overdose OR overdose.mp] LIMIT to English language
Altogether 95 papers were found. Two papers were relevant to the three part question.
|Author, date and country
||Study type (level of evidence)
|Chin RL et al,|
|88 patients with GHB ingestion. 1993-1996. Single ED in San Francisco. 11/88 patients were intubated||Retrospective note review over a 3 year period||Intubation||13% (11) intubated. 73% (8) of those intubated had GCS 3, 27% (3) had GCS 4-7. 73% also had bradycardia. Mean duration of intubation = 179 mins. 9 of these were admitted for 24 hrs. 2 were discharged directly||Retrospective analysis. GHB ingestion confirmed from case notes, not toxicological testing
Clinical picture of GHB toxication often complicated by other substances
Differences in recovery time may reflect use of sedative agents during intubation, or the initial severity of presentation among intubated group|
|Co-ingestion of other drugs||Co-ingestion: 39% (34) alcohol, 28% (25) other drugs|
|Time to regaining conciousness||Intubation related to recovery time: mean time to recovery among non-intubated = 146 mins (16-389). Mean time to recovery among intubated = 274 mins (161-439)|
|Aspiration||No record of aspiration in any patient|
|GCS||28% (25) GCS=3, 32% (28) GCS=4-8, 40% (35) GCS=9-15|
|Li J et al,|
|7 patients with GHB ingestion, identified by urine spectrometry||Case Report||Aspiration||No record of aspiration||Case report
Small number of patients
No record of any adverse events|
|No intubation||1 patient not intubated|
|Time to extubation||Time to extubation 6, 4, 2 and 2 hrs. 1 patient required sedation|
|Atempted intubation||2 failed intubations, patients observed thereafter|
|Pre-hospital GCS||6 had GCS <9, 1 had GCS >9|
The evidence for and against endotracheal intubation is scanty. These reports suggest show no evidence for aspiration but the numbers involved (of non-intubated patients) are small. There is insufficient evidence here to change the standard approach to airway management in the unconcious patient. The reduced GCS is an indication for airway protection that would normally be achieved using a rapid sequence induction of anaesthesia.
Updated May 2004 - no new papers
Comments and bottom line amended by SDC September 2004
Clinical Bottom Line
In patients with suspected GHB toxicity, reduced GCS and a threatened airway, rapid sequence induction and intubation should be performed.
Level of Evidence
Level 3 - Small numbers of small studies or great heterogeneity or very different population.
- Chin RL, Sporer KA, Cullison B et al. Clinical course of gamma-hydroxybutyrate overdose. Ann Emerg Med 1998;31(6):716-22.
- Li J, Stokes SA, Woeckener A. A Tale of Novel Intoxication: Seven cases of gamma-hydroxybutyric acid overdose. Ann Emerg Med 1998;31(6):723-28.